Simultaneous Beam Scanning and Wavefront Shaping in Moiré Metagratings

Moiré optics offers a versatile degree of freedom for dynamic beam manipulation through relative twisting of a pair of closely stacked metasurfaces. Previous studies either focus on pure beam direction control or wavefront transformation, but not both. In fact, different phase functions can be superimposed in each layer, and the twisting may lead to increased flexibility. Following this idea, we develop a general source-to-end model to simultaneously modulate the beam direction and the wavefront in real time. The point-to-point scanning, the Bessel beam scanning with controllable non-diffraction distance or with controllable topological orders are experimentally demonstrated. The beam scanning field of view covers ±60° with around 40% measured wavefront shaping efficiency. The study here may find applications in wireless communications for dynamic energy and signal transfer.